Wasn't the recommended dosage like 500mg of -(-)epi tho? I thought it was higher than 300... Plus, the extract would make a diff so if yours is yielding less functional product that would make it even worse... Just my speculation/thought.
AFAIK, there have been two studies that directly relate to athletic performance (could be more, I'm by no means obsessively researching it). The first one, which showed a decrease/increase in Myostatin/Follistatin is here, which used 75mg twice a day. Jan 2014:
h t t p : / / w w w .ncbi.nlm.nih.gov/pubmed/24314870/
Then there was the recent one, which only measured blood plasma concentrations at different dosages, showing 200mg was better than less (they went no higher than 200mg IIRC).
As far as the extract, well, I guess a NutraPlanet rep can chime in, but looking at the offerings/prices from Sigma-Aldrich, it would be pretty stupid to sell bunk -(-)Epi... but you could have a point, so that's fair.
The non-responder critique is fair too... though I find that it is used as a 'catch all' too. So far I am a non-responder to -(-)Epi, Amentoflavone, and Intra-Workout BCAA/EAA
Set a High-Bar Squat PR in the 8-12 rep Range yesterday, so the hits just keep on rolling
To everyone else, thanks - believe me, I am a supplement whore!.... for the stuff that has a ton of data. Unfortunately, the quantity of those isn't as much as the quantity of the rest of the market.